What am i missing? WRT54GS v.4 related

I was able to get ping responses by joining pin 15-16 with a screewdriver , I also did the arp procedure of adding the router's mac address (static) but when i try to install the linksys firmware here is what happens:

C:\>tftp -i 192.168.1.1 put c:\code.bin
Transfer successful: 2884608 bytes in 8 seconds, 360576 bytes/s
(I also tried using the original filename instead of code.bin and still the same problem)